llvm/lib/Target/X86/X86ScheduleBtVer2.td
Andrea Di Biagio a5ab9baf83 [X86][SchedModel] SSE reciprocal square root instruction latencies.
The SSE rsqrt instruction (a fast reciprocal square root estimate) was
grouped in the same scheduling IIC_SSE_SQRT* class as the accurate (but very
slow) SSE sqrt instruction. For code which uses rsqrt (possibly with
newton-raphson iterations) this poor scheduling was affecting performances.

This patch splits off the rsqrt instruction from the sqrt instruction scheduling
classes and creates new IIC_SSE_RSQER* classes with latency values based on
Agner's table.

Differential Revision: http://reviews.llvm.org/D5370

Patch by Simon Pilgrim.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218517 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-26 12:56:44 +00:00

342 lines
11 KiB
TableGen

//=- X86ScheduleBtVer2.td - X86 BtVer2 (Jaguar) Scheduling ---*- tablegen -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the machine model for AMD btver2 (Jaguar) to support
// instruction scheduling and other instruction cost heuristics. Based off AMD Software
// Optimization Guide for AMD Family 16h Processors & Instruction Latency appendix.
//
//===----------------------------------------------------------------------===//
def BtVer2Model : SchedMachineModel {
// All x86 instructions are modeled as a single micro-op, and btver2 can
// decode 2 instructions per cycle.
let IssueWidth = 2;
let MicroOpBufferSize = 64; // Retire Control Unit
let LoadLatency = 5; // FPU latency (worse case cf Integer 3 cycle latency)
let HighLatency = 25;
let MispredictPenalty = 14; // Minimum branch misdirection penalty
let PostRAScheduler = 1;
// FIXME: SSE4/AVX is unimplemented. This flag is set to allow
// the scheduler to assign a default model to unrecognized opcodes.
let CompleteModel = 0;
}
let SchedModel = BtVer2Model in {
// Jaguar can issue up to 6 micro-ops in one cycle
def JALU0 : ProcResource<1>; // Integer Pipe0: integer ALU0 (also handle FP->INT jam)
def JALU1 : ProcResource<1>; // Integer Pipe1: integer ALU1/MUL/DIV
def JLAGU : ProcResource<1>; // Integer Pipe2: LAGU
def JSAGU : ProcResource<1>; // Integer Pipe3: SAGU (also handles 3-operand LEA)
def JFPU0 : ProcResource<1>; // Vector/FPU Pipe0: VALU0/VIMUL/FPA
def JFPU1 : ProcResource<1>; // Vector/FPU Pipe1: VALU1/STC/FPM
// Any pipe - FIXME we need this until we can discriminate between int/fpu load/store/moves properly
def JAny : ProcResGroup<[JALU0, JALU1, JLAGU, JSAGU, JFPU0, JFPU1]>;
// Integer Pipe Scheduler
def JALU01 : ProcResGroup<[JALU0, JALU1]> {
let BufferSize=20;
}
// AGU Pipe Scheduler
def JLSAGU : ProcResGroup<[JLAGU, JSAGU]> {
let BufferSize=12;
}
// Fpu Pipe Scheduler
def JFPU01 : ProcResGroup<[JFPU0, JFPU1]> {
let BufferSize=18;
}
def JDiv : ProcResource<1>; // integer division
def JMul : ProcResource<1>; // integer multiplication
def JVALU0 : ProcResource<1>; // vector integer
def JVALU1 : ProcResource<1>; // vector integer
def JVIMUL : ProcResource<1>; // vector integer multiplication
def JSTC : ProcResource<1>; // vector store/convert
def JFPM : ProcResource<1>; // FP multiplication
def JFPA : ProcResource<1>; // FP addition
// Integer loads are 3 cycles, so ReadAfterLd registers needn't be available until 3
// cycles after the memory operand.
def : ReadAdvance<ReadAfterLd, 3>;
// Many SchedWrites are defined in pairs with and without a folded load.
// Instructions with folded loads are usually micro-fused, so they only appear
// as two micro-ops when dispatched by the schedulers.
// This multiclass defines the resource usage for variants with and without
// folded loads.
multiclass JWriteResIntPair<X86FoldableSchedWrite SchedRW,
ProcResourceKind ExePort,
int Lat> {
// Register variant is using a single cycle on ExePort.
def : WriteRes<SchedRW, [ExePort]> { let Latency = Lat; }
// Memory variant also uses a cycle on JLAGU and adds 3 cycles to the
// latency.
def : WriteRes<SchedRW.Folded, [JLAGU, ExePort]> {
let Latency = !add(Lat, 3);
}
}
multiclass JWriteResFpuPair<X86FoldableSchedWrite SchedRW,
ProcResourceKind ExePort,
int Lat> {
// Register variant is using a single cycle on ExePort.
def : WriteRes<SchedRW, [ExePort]> { let Latency = Lat; }
// Memory variant also uses a cycle on JLAGU and adds 5 cycles to the
// latency.
def : WriteRes<SchedRW.Folded, [JLAGU, ExePort]> {
let Latency = !add(Lat, 5);
}
}
// A folded store needs a cycle on the SAGU for the store data.
def : WriteRes<WriteRMW, [JSAGU]>;
////////////////////////////////////////////////////////////////////////////////
// Arithmetic.
////////////////////////////////////////////////////////////////////////////////
defm : JWriteResIntPair<WriteALU, JALU01, 1>;
defm : JWriteResIntPair<WriteIMul, JALU1, 3>;
def : WriteRes<WriteIMulH, [JALU1]> {
let Latency = 6;
let ResourceCycles = [4];
}
// FIXME 8/16 bit divisions
def : WriteRes<WriteIDiv, [JALU1, JDiv]> {
let Latency = 25;
let ResourceCycles = [1, 25];
}
def : WriteRes<WriteIDivLd, [JALU1, JLAGU, JDiv]> {
let Latency = 41;
let ResourceCycles = [1, 1, 25];
}
// This is for simple LEAs with one or two input operands.
// FIXME: SAGU 3-operand LEA
def : WriteRes<WriteLEA, [JALU01]>;
////////////////////////////////////////////////////////////////////////////////
// Integer shifts and rotates.
////////////////////////////////////////////////////////////////////////////////
defm : JWriteResIntPair<WriteShift, JALU01, 1>;
////////////////////////////////////////////////////////////////////////////////
// Loads, stores, and moves, not folded with other operations.
// FIXME: Split x86 and SSE load/store/moves
////////////////////////////////////////////////////////////////////////////////
def : WriteRes<WriteLoad, [JLAGU]> { let Latency = 5; }
def : WriteRes<WriteStore, [JSAGU]>;
def : WriteRes<WriteMove, [JAny]>;
////////////////////////////////////////////////////////////////////////////////
// Idioms that clear a register, like xorps %xmm0, %xmm0.
// These can often bypass execution ports completely.
////////////////////////////////////////////////////////////////////////////////
def : WriteRes<WriteZero, []>;
////////////////////////////////////////////////////////////////////////////////
// Branches don't produce values, so they have no latency, but they still
// consume resources. Indirect branches can fold loads.
////////////////////////////////////////////////////////////////////////////////
defm : JWriteResIntPair<WriteJump, JALU01, 1>;
////////////////////////////////////////////////////////////////////////////////
// Floating point. This covers both scalar and vector operations.
// FIXME: should we bother splitting JFPU pipe + unit stages for fast instructions?
// FIXME: Double precision latencies
// FIXME: SS vs PS latencies
// FIXME: ymm latencies
////////////////////////////////////////////////////////////////////////////////
defm : JWriteResFpuPair<WriteFAdd, JFPU0, 3>;
defm : JWriteResFpuPair<WriteFMul, JFPU1, 2>;
defm : JWriteResFpuPair<WriteFRcp, JFPU1, 2>;
defm : JWriteResFpuPair<WriteFRsqrt, JFPU1, 2>;
defm : JWriteResFpuPair<WriteFShuffle, JFPU01, 1>;
defm : JWriteResFpuPair<WriteFBlend, JFPU01, 1>;
defm : JWriteResFpuPair<WriteFShuffle256, JFPU01, 1>;
def : WriteRes<WriteFSqrt, [JFPU1, JLAGU, JFPM]> {
let Latency = 21;
let ResourceCycles = [1, 1, 21];
}
def : WriteRes<WriteFSqrtLd, [JFPU1, JLAGU, JFPM]> {
let Latency = 26;
let ResourceCycles = [1, 1, 21];
}
def : WriteRes<WriteFDiv, [JFPU1, JLAGU, JFPM]> {
let Latency = 19;
let ResourceCycles = [1, 1, 19];
}
def : WriteRes<WriteFDivLd, [JFPU1, JLAGU, JFPM]> {
let Latency = 24;
let ResourceCycles = [1, 1, 19];
}
// FIXME: integer pipes
defm : JWriteResFpuPair<WriteCvtF2I, JFPU1, 3>; // Float -> Integer.
defm : JWriteResFpuPair<WriteCvtI2F, JFPU1, 3>; // Integer -> Float.
defm : JWriteResFpuPair<WriteCvtF2F, JFPU1, 3>; // Float -> Float size conversion.
def : WriteRes<WriteFVarBlend, [JFPU01]> {
let Latency = 2;
let ResourceCycles = [2];
}
def : WriteRes<WriteFVarBlendLd, [JLAGU, JFPU01]> {
let Latency = 7;
let ResourceCycles = [1, 2];
}
// Vector integer operations.
defm : JWriteResFpuPair<WriteVecALU, JFPU01, 1>;
defm : JWriteResFpuPair<WriteVecShift, JFPU01, 1>;
defm : JWriteResFpuPair<WriteVecIMul, JFPU0, 2>;
defm : JWriteResFpuPair<WriteShuffle, JFPU01, 1>;
defm : JWriteResFpuPair<WriteBlend, JFPU01, 1>;
defm : JWriteResFpuPair<WriteVecLogic, JFPU01, 1>;
defm : JWriteResFpuPair<WriteShuffle256, JFPU01, 1>;
def : WriteRes<WriteVarBlend, [JFPU01]> {
let Latency = 2;
let ResourceCycles = [2];
}
def : WriteRes<WriteVarBlendLd, [JLAGU, JFPU01]> {
let Latency = 7;
let ResourceCycles = [1, 2];
}
// FIXME: why do we need to define AVX2 resource on CPU that doesn't have AVX2?
def : WriteRes<WriteVarVecShift, [JFPU01]> {
let Latency = 1;
let ResourceCycles = [1];
}
def : WriteRes<WriteVarVecShiftLd, [JLAGU, JFPU01]> {
let Latency = 6;
let ResourceCycles = [1, 1];
}
def : WriteRes<WriteMPSAD, [JFPU0]> {
let Latency = 3;
let ResourceCycles = [2];
}
def : WriteRes<WriteMPSADLd, [JLAGU, JFPU0]> {
let Latency = 8;
let ResourceCycles = [1, 2];
}
////////////////////////////////////////////////////////////////////////////////
// String instructions.
// Packed Compare Implicit Length Strings, Return Mask
// FIXME: approximate latencies + pipe dependencies
////////////////////////////////////////////////////////////////////////////////
def : WriteRes<WritePCmpIStrM, [JFPU01]> {
let Latency = 7;
let ResourceCycles = [2];
}
def : WriteRes<WritePCmpIStrMLd, [JLAGU, JFPU01]> {
let Latency = 12;
let ResourceCycles = [1, 2];
}
// Packed Compare Explicit Length Strings, Return Mask
def : WriteRes<WritePCmpEStrM, [JFPU01]> {
let Latency = 13;
let ResourceCycles = [5];
}
def : WriteRes<WritePCmpEStrMLd, [JLAGU, JFPU01]> {
let Latency = 18;
let ResourceCycles = [1, 5];
}
// Packed Compare Implicit Length Strings, Return Index
def : WriteRes<WritePCmpIStrI, [JFPU01]> {
let Latency = 6;
let ResourceCycles = [2];
}
def : WriteRes<WritePCmpIStrILd, [JLAGU, JFPU01]> {
let Latency = 11;
let ResourceCycles = [1, 2];
}
// Packed Compare Explicit Length Strings, Return Index
def : WriteRes<WritePCmpEStrI, [JFPU01]> {
let Latency = 13;
let ResourceCycles = [5];
}
def : WriteRes<WritePCmpEStrILd, [JLAGU, JFPU01]> {
let Latency = 18;
let ResourceCycles = [1, 5];
}
////////////////////////////////////////////////////////////////////////////////
// AES Instructions.
////////////////////////////////////////////////////////////////////////////////
def : WriteRes<WriteAESDecEnc, [JFPU01, JVIMUL]> {
let Latency = 3;
let ResourceCycles = [1, 1];
}
def : WriteRes<WriteAESDecEncLd, [JFPU01, JLAGU, JVIMUL]> {
let Latency = 8;
let ResourceCycles = [1, 1, 1];
}
def : WriteRes<WriteAESIMC, [JVIMUL]> {
let Latency = 2;
let ResourceCycles = [1];
}
def : WriteRes<WriteAESIMCLd, [JLAGU, JVIMUL]> {
let Latency = 7;
let ResourceCycles = [1, 1];
}
def : WriteRes<WriteAESKeyGen, [JVIMUL]> {
let Latency = 2;
let ResourceCycles = [1];
}
def : WriteRes<WriteAESKeyGenLd, [JLAGU, JVIMUL]> {
let Latency = 7;
let ResourceCycles = [1, 1];
}
////////////////////////////////////////////////////////////////////////////////
// Carry-less multiplication instructions.
////////////////////////////////////////////////////////////////////////////////
def : WriteRes<WriteCLMul, [JVIMUL]> {
let Latency = 2;
let ResourceCycles = [1];
}
def : WriteRes<WriteCLMulLd, [JLAGU, JVIMUL]> {
let Latency = 7;
let ResourceCycles = [1, 1];
}
// FIXME: pipe for system/microcode?
def : WriteRes<WriteSystem, [JAny]> { let Latency = 100; }
def : WriteRes<WriteMicrocoded, [JAny]> { let Latency = 100; }
def : WriteRes<WriteFence, [JSAGU]>;
def : WriteRes<WriteNop, []>;
} // SchedModel